Transmission colored glasses

Metal nanoparticles have been used for many applications because of their unique characteristics, even before they were visualized as small particles of nano-meter order by using a transmission electron microscope [118]. For example, colored glasses, which gained in popularity in medieval times, contain nanoparticles of noble metals. These colors originate from the SPR of metal nanoparticles, which is the resonance phenomenon of surface electron density wave with incident light wave at the metal surface [119]. Since this resonance is sensitive to the dielectric constant of surrounding media, the phenomenon has... 

For colored glass containers, not intended for parenteral preparations, the measured transmission must not exceed a maximum value of 10% at any wavelength between 290 and 450 nm, irrespective of the size or glass type. The limits for colored glass containers, used for parenteral preparations, depend on their intended fill volume. The respective limits for these containers are given in Table 1 (3,4). 

Figure 4 Transmission curves of differently green-colored glass compared to flint and brown giass. (1) Fiint, (2) Georgia green, (3) emerald green, (4) UV absorbing green, (5) champagne green, (6) amber. Source From Ref. 16.

According to the Lambert-Beer s law, the absorption increases with the layer thickness. The higher the absorption, the better will be the photo protective properties of the container. Depending on the intended purpose the layer thickness of the glass container is limited to a certain extent. This fact is also considered in the pharmacopoeial tests for the transmission of colored glass containers, where higher transmission values are acceptable (3,4). 

The photon transmissive properties of colored glass containers vary considerably with their thickness and absorptivity. Stewart and Tucker (24) considered... 

At the specular angle we see the blue from the interference pigment. At the diffuse angle we see the red from the absorption colorant which has been precipitated on the surface. By transmission, a third color is formed which is not often seen unless coated on a transparent substrate such as glass or Mylar. The transmission color from the interference pigment which is yellow has combined with the absorption colorant which is red to form a third color which is orange. 

When measurements were made at -15/15, a black card was placed behind the coated glass slides to eliminate the effect of the transmission color. When measurements were made at -15/60, a white card was placed behind the coated glass slide. A diagram demonstrating the position of the slides and the cards is shown in Figure 7. 

The optimum light collection geometry for chemiluminescent solutions uses an ellipsoidal reflector with the light source at one focus and a cooled phototube photocathode at the other. Individual colored glass filters are placed near the face of the phototube and the emission spectrum is determined by the differences in filter transmissions. With this idealized system the authors report a sensitivity such that their noise equivalent signal at 500 nm and a bandwidth of 30 nm is (Inaba et at., 1979)... 

Plastics range from opaque to transparent. Many have greater transmission than glass. In plastics, the extent of ttansmission and wave scattering is independent of wavelength, and plastics in their purest form have no color of their own. As impurities are introduced, a plastic becomes more translucent than opaque and begins to acquire a yellowish tinge. 

In simple equipment, only relatively wide transmission bands are selected by means of colored glass or interference filters. A working beam of narrow bandwidth is obtained by combining this with a mercury source. Interference filters give spectral bandwidths in the 3-10-nm range [42], [68]. These operate on the principle of multiple reflections between layers of dielectric material that have been produced in a definite sequence by vacuum deposition. The wave character of light leads to interference of the reflected beams at... 

W. Pannhorst, E. Rodek, H. Scheidler Transparent colored glass ceramic with good thermal stability and variable transmission in the IR region , U.S. Pat. No. 5,212,122, May 18, 1993... 

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